1,661 research outputs found
Written Reflection Influences Science Studentsâ Perceptions of Their Own and Their Peersâ Teamwork and Related Employability Skills
The impact of written reflection on tertiary studentsâ self-efficacy, and corresponding evaluation of their peersâ abilities, is often imprecise and lacking in clarity. This study thus sought to assess the effects of a written reflective diary on science undergraduatesâ teamwork-related and other employability skills. Employability skills, in particular studentsâ teamwork-related skills, are crucial to studentsâ career development and progression. Assessment was carried out using a series of pre- and post-reflection online surveys, the TeamQ assessment rubric, and student focus groups. Participants identified five key teamwork skills, the importance of which remained constant over time. Written reflection had a significant, positive effect on studentsâ self-efficacy of their oral communication skills. Studentsâ written reflections were also important in shaping their perceptions about the domain of fostering a team climate, both in terms of their own self-efficacy and perceptions of their peersâ abilities. This study has interesting implications for future research into science studentsâ teamwork and other employability skills
Herschel observations of star-forming regions from the HOBYS programme
This thesis presents three higher-mass star forming regions (Mon R1, Mon R2 and
NGC 2264) as observed by Herschel, and also the JCMT (SCUBA-2), and the IRAM
30-m telescope, with additional data from the Spitzer and WISE archives. The Herschel
observations, using the SPIRE and PACS instruments over a range of 70 m{500 m,
were taken as part of the HOBYS Key Programme, and the data were reduced using
the HIPE mapmaking environment with sources identified and characterised by the get-
sources routine. The Herschel observations cover the peaks of cold dust SEDs, allowing
robust estimates of mass and temperature to be made.
Comparisons of the Herschel observations of the three regions suggest a picture
of star formation in which the densest parts of certain molecular clouds can accrete
matter via filaments from the surrounding regions, fuelling far more star formation
than occurs in the outer regions. My study of these regions has led to the potential
classification of two separate regimes of star formation. The �first occurs in �filamentary
regions (generally observed with a column density of 3 ďż˝ 1021 c
Goodness-of-fit tests of Gaussianity: constraints on the cumulants of the MAXIMA data
In this work, goodness-of-fit tests are adapted and applied to CMB maps to
detect possible non-Gaussianity. We use Shapiro-Francia test and two Smooth
goodness-of-fit tests: one developed by Rayner and Best and another one
developed by Thomas and Pierce. The Smooth tests test small and smooth
deviations of a prefixed probability function (in our case this is the
univariate Gaussian). Also, the Rayner and Best test informs us of the kind of
non-Gaussianity we have: excess of skewness, of kurtosis, and so on. These
tests are optimal when the data are independent. We simulate and analyse
non-Gaussian signals in order to study the power of these tests. These
non-Gaussian simulations are constructed using the Edgeworth expansion, and
assuming pixel-to-pixel independence. As an application, we test the
Gaussianity of the MAXIMA data. Results indicate that the MAXIMA data are
compatible with Gaussianity. Finally, the values of the skewness and kurtosis
of MAXIMA data are constrained by |S| \le 0.035 and |K| \le 0.036 at the 99%
confidence level.Comment: New Astronomy Reviews, in pres
Confirmation of Enhanced Dwarf-sensitive Absorption Features in the Spectra of Massive Elliptical Galaxies: Further Evidence for a Non-universal Initial Mass Function
We recently found that massive cluster elliptical galaxies have strong Na I
8183,8195 and FeH 9916 Wing-Ford band absorption, indicating the presence of a
very large population of stars with masses <~ 0.3 M_sun. Here we test this
result by comparing the elliptical galaxy spectra to those of luminous globular
clusters associated with M31. These globular clusters have similar
metallicities, abundance ratios and ages as massive elliptical galaxies but
their low dynamical mass-to-light ratios rule out steep stellar initial mass
functions (IMFs). From high quality Keck spectra we find that the
dwarf-sensitive absorption lines in globular clusters are significantly weaker
than in elliptical galaxies, and consistent with normal IMFs. The differences
in the Na I and Wing-Ford indices are 0.027 +- 0.007 mag and 0.017 +- 0.006 mag
respectively. We directly compare the two classes of objects by subtracting the
averaged globular cluster spectrum from the averaged elliptical galaxy
spectrum. The difference spectrum is well fit by the difference between a
stellar population synthesis model with a bottom-heavy IMF and one with a
bottom-light IMF. We speculate that the slope of the IMF may vary with velocity
dispersion, although it is not yet clear what physical mechanism would be
responsible for such a relation.Comment: Published in ApJ Letter
Quantitative insertion-site sequencing (QIseq) for high throughput phenotyping of transposon mutants
Genetic screening using random transposon insertions has been a powerful tool for uncovering biology in prokaryotes, where whole-genome saturating screens have been performed in multiple organisms. In eukaryotes, such screens have proven more problematic, in part because of the lack of a sensitive and robust system for identifying transposon insertion sites. We here describe quantitative insertion-site sequencing, or QIseq, which uses custom library preparation and Illumina sequencing technology and is able to identify insertion sites from both the 5' and 3' ends of the transposon, providing an inbuilt level of validation. The approach was developed using piggyBac mutants in the human malaria parasite Plasmodium falciparum but should be applicable to many other eukaryotic genomes. QIseq proved accurate, confirming known sites in >100 mutants, and sensitive, identifying and monitoring sites over a >10,000-fold dynamic range of sequence counts. Applying QIseq to uncloned parasites shortly after transfections revealed multiple insertions in mixed populations and suggests that >4000 independent mutants could be generated from relatively modest scales of transfection, providing a clear pathway to genome-scale screens in P. falciparum QIseq was also used to monitor the growth of pools of previously cloned mutants and reproducibly differentiated between deleterious and neutral mutations in competitive growth. Among the mutants with fitness defects was a mutant with a piggyBac insertion immediately upstream of the kelch protein K13 gene associated with artemisinin resistance, implying mutants in this gene may have competitive fitness costs. QIseq has the potential to enable the scale-up of piggyBac-mediated genetics across multiple eukaryotic systems
Goodness-of-Fit Tests to study the Gaussianity of the MAXIMA data
Goodness-of-Fit tests, including Smooth ones, are introduced and applied to
detect non-Gaussianity in Cosmic Microwave Background simulations. We study the
power of three different tests: the Shapiro-Francia test (1972), the
uncategorised smooth test developed by Rayner and Best(1990) and the Neyman's
Smooth Goodness-of-fit test for composite hypotheses (Thomas and Pierce 1979).
The Smooth Goodness-of-Fit tests are designed to be sensitive to the presence
of ``smooth'' deviations from a given distribution. We study the power of these
tests based on the discrimination between Gaussian and non-Gaussian
simulations. Non-Gaussian cases are simulated using the Edgeworth expansion and
assuming pixel-to-pixel independence. Results show these tests behave similarly
and are more powerful than tests directly based on cumulants of order 3, 4, 5
and 6. We have applied these tests to the released MAXIMA data. The applied
tests are built to be powerful against detecting deviations from univariate
Gaussianity. The Cholesky matrix corresponding to signal (based on an assumed
cosmological model) plus noise is used to decorrelate the observations previous
to the analysis. Results indicate that the MAXIMA data are compatible with
Gaussianity.Comment: MNRAS, in pres
Hippocampal c-Jun-N-terminal kinases serve as negative regulators of associative learning
In the adult mouse, signaling through c-Jun N-terminal kinases (JNKs) links exposure to acute stress to various physiological responses. Inflammatory cytokines, brain injury and ischemic insult, or exposure to psychological acute stressors induce activation of hippocampal JNKs. Here we report that exposure to acute stress caused activation of JNKs in the hippocampal CA1 and CA3 subfields, and impaired contextual fear conditioning. Conversely, intrahippocampal injection of JNKs inhibitors sp600125 (30 mum) or D-JNKI1 (8 mum) reduced activity of hippocampal JNKs and rescued stress-induced deficits in contextual fear. In addition, intrahippocampal administration of anisomycin (100 mug/mul), a potent JNKs activator, mimicked memory-impairing effects of stress on contextual fear. This anisomycin-induced amnesia was abolished after cotreatment with JNKs selective inhibitor sp600125 without affecting anisomycin\u27s ability to effectively inhibit protein synthesis as measured by c-Fos immunoreactivity. We also demonstrated milder and transient activation of the JNKs pathway in the CA1 subfield of the hippocampus during contextual fear conditioning and an enhancement of contextual fear after pharmacological inhibition of JNKs under baseline conditions. Finally, using combined biochemical and transgenic approaches with mutant mice lacking different members of the JNK family (Jnk1, Jnk2, and Jnk3), we provided evidence that JNK2 and JNK3 are critically involved in stress-induced deficit of contextual fear, while JNK1 mainly regulates baseline learning in this behavioral task. Together, these results support the possibility that hippocampal JNKs serve as a critical molecular regulator in the formation of contextual fear
Fresh Waters and Fish Diversity: Distribution, Protection and Disturbance in Tropical Australia
Background: Given the globally poor protection of fresh waters for their intrinsic ecological values, assessments are needed to determine how well fresh waters and supported fish species are incidentally protected within existing terrestrial protected-area networks, and to identify their vulnerability to human-induced disturbances. To date, gaps in data have severely constrained any attempt to explore the representation of fresh waters in tropical regions.\ud
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Methodology and Results: We determined the distribution of fresh waters and fish diversity in the Wet Tropics of Queensland, Australia. We then used distribution data of fresh waters, fish species, human-induced disturbances, and the terrestrial protected-area network to assess the effectiveness of terrestrial protected areas for fresh waters and fish species. We also identified human-induced disturbances likely to influence the effectiveness of freshwater protection and evaluated the vulnerability of fresh waters to these disturbances within and outside protected areas. The representation of fresh waters and fish species in the protected areas of the Wet Tropics is poor: 83% of stream types defined by order, 75% of wetland types, and 89% of fish species have less than 20% of their total Wet Tropics length, area or distribution completely within IUCN category II protected areas. Numerous disturbances affect fresh waters both within and outside of protected areas despite the high level of protection afforded to terrestrial areas in the Wet Tropics (>60% of the region). High-order streams and associated wetlands are influenced by the greatest number of human-induced disturbances and are also the least protected. Thirty-two percent of stream length upstream of protected areas has at least one human-induced disturbance present.\ud
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Conclusions/Significance: We demonstrate the need for greater consideration of explicit protection and off-reserve management for fresh waters and supported biodiversity by showing that, even in a region where terrestrial protection is high, it does not adequately capture fresh waters
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